BIO 460 Exam 2: Back Region

What is the action of the right splenius capitis?

-The muscle flexes and rotates the head and neck to the same side - left to left, right to right -Splenius muscles have an ipsilateral lateral flexion and rotation movement

Where should an epidural injection be performed? How?

-Through the Ligamentum Flavum - epidural fat -past the conus medullaris

Where are the preganglionic cell bodies found? What type(s) of neurons do they synapse with?

- T1-L2 (where lateral horns are found) - Post-ganglionic cell bodies that are found in the sympathetic chain ganglion

What ligaments are derived of Pía mater and anchor the spinal cord? How do these anchor the spinal cord?

- denticulate ligament anchor the SC laterally and filum terminale anchor SC longitudinally -pierce the arachnoid to attach to the inner aspect of the dura mater at 21 pairs of denticulations (dentate means tooth-like - these are tooth-like lateral projections)

What are the regional characteristics of the vertebrae: Lumbar

-Large Bodies -Blunt Spinous P + Transverse (Hatchet Like) -Weight Bearing -Prone to Herniations & other back problems -Lumbosacral Angle: 30-50 degrees -L1-L2 Spinal Cord Ends

What are the regional characteristics of the vertebrae: Thoracic

-Long Spinous Process -Ribs Attach Here: Costal & Demifacet -Medium Sized Bodies -Spinal Cord Here will have Lateral Horns T1-L2 Different Spinal Cord Structure

Which muscles are considered Intermediate (extrinsic) back muscles?

-Serratus posterior Inferior -Serratus Posterior Superior

What muscles deal mainly with proprioception?

-Serratus posterior superior -Serratus Posterior Inferior -Serratus Anterior - Transversospinalis: Rotatores

Rib 11 articulates with:

-Superior demifacet of Tll -Inferior demifacet of T10

Where does the filum termínale attach? Where do the denticulate ligaments attach?

-The filum terminale attaches distally to the coccyx -The denticulate ligaments are bilateral triangular lateral extensions of pia mater that anchor the spinal cord to the dura mater (or dural sac)

What are the steps to DDX?

1) Observations -physical abnormalities 2) Questions -Medical hx -Chief complaint -Family Medical hx 3) Physical Exam (least invasive to most invasive) a. ROM - Active movement (Pt performs) -Passive movement (Doctor performs) b. Palpation (poke)/ Percussion (tapping)/ Auscultation (stethoscope) c. Orthopedic Tests (challenge anatomy) d. Neurological Tests - Sensory (light, touch, sharp vs dull) - Motor (resisted muscle test) e. Imaging (if needed) - x-ray, CT, MRI, Ultrasound f. Lab tests (if needed) - Urinalysis, stool, blood 4) Predict different DIAGNOSIS

Causes of scoliosis:

1. *Idiopathic* 80% some pts have FHx 2. *Congenital* - malformation vertebrae 3. *Neuromuscular* - muscular weakness/spasticity (poliomyelitis, cerebral palsy, Duchenne's, meningomyelocele) 4. *Acquired*- tumor, infection, osteomalacia, sciatic irritability, psoas syndrome, short left syndrome

SA // ME DA // VE

SA Sensory neuron Afferent ( Tissue ---> CNS) DA Dorsal horn Afferent ME Motor neuron Efferent (CNS ----> muscle) VE Ventral horn Efferent

What is an abnormal lateral curvature of the vertebral column? Most common curvature. How is it curved?

Scoliosis, right thoracic and left lumbar

Which ligament prevents hyperextension of the back?

Anterior Longitudinal Ligament

What it's the joint atlas and the axis called?

Atlanto-axial joint

What is the origin & insertion of the rectus capitis posterior major?

Origin: the spinous process of the C2 vertebrae (axis) Insertion: into the lateral part of the inferior nuchal line of the occipital bone

What is the function of the parasympathetic nervous system?

The parasympathetic nervous system controls bodily functions when a person is at rest. Some of its activities include stimulating digestion, activating metabolism, and helping the body relax

Lordosis

a normal anterior curve of the cervical and lumbar spine. ((<---Back curves this way

kyphosis

a normal posterior curve of the thoracic and sacral spine. Back curves this way--> ))

Scoliosis

an abnormal lateral curvature of the spine

What is a root sleeve? What does it protect?

an extension of the dura mater that surrounds the spinal nerves of the spinal cord as they exit the vertebral column

What are the parts of the intervertebral discs?

annulus fibrosus (hard outside layer) and nucleus pulposus (soft inside)

Which of the following is not a type of bone cell? -osteoblast -osteocyte -osteoclast -chondroblast

chondroblast

Hypokyphosis

decrease in natural thoracic curvature - occurs with spinal correcting surgeries

Hyperlordosis

exaggerated anterior lumbar curvature (swayback) -occurs with pregnancy

When do the primary curvatures develop?

fetal development

Which structure articulates with the demifacets?

head of the rib

What ligament is segmented from lamina to lamina?

ligamentum flavum

The vertebral arteries converge cephalically into which structure?

the basilar artery

What innervates the latísimus dorsi?

the thoracodorsal nerve (from the posterior cord of the brachial plexus)

Which ligament holds the dens in place?

transverse ligament

Which structure articulates with the transverse costal facets?

tubercle of the rib

What is the function of the Axis?

turn head side to side

What prevents hyperflexion of the neck? Back?

Neck: Nuchal ligament Back: Interspinous ligament & Supraspinous ligament

Which ligament passes through the bifid spinous processes of the cervical vertebra?

Nuchal ligament

What is a herniated disc?

Nucleus pulposus grows outside of the Annulus fibrosus b/c of a tear and will then impinge on a spinal nerve most commonly in the posterolateral direction

Which is the first prominent vertebra on the spine? Why?

- C7 -Because the nuchal ligament end at C7 and then begins the thoracic region of the spine in which is held together by the Supraspinous ligament

If car A (at 0 mph) is hit from behind by car B (going 300 mph). What ligament injury will the driver in car A suffer from? What ligament injury will the driver in car B suffer from?

- Car A: Hyperextension of the Anterior Longitudinal ligament - Car B: Hyperflexion of the Nuchal ligament in the neck and the interspinous/Supraspinous ligament in the back

What is the name of the motor pathway? What is it's function? Ascending or descending? Ipsilateral or Contralateral?

- Corticospinal Tract - signals from the brain all motor movement - Descending (from thalamus) - Ipsilateral (crosses in the medulla)

If a lesion occurs on the left side of the spinal cord, what functions will we lose on which side?

- Motor on the left side - sensory on the left - pain and temp on the right

The suboccipital triangle is directly surrounded by which muscles? What are their insertions and origins? What structures lie in the middle of the triangle?

- Rectus capitis posterior Major Origin: C2 spine Insertion: Sup/ Inf nuchal lines -Obliquus capitis superior Origin: transverse process of C1 Insertion: Sup/Inf nuchal lines -Obliquus capitis inferior Origin: C2 spine Insertion: transverse process of C1 -Rectus Capitis Posterior Minor ***NOT DIRECTLY APART OF TRI. Origin: Arch of C1 Insertion: Inf. Nuchal Line -The vertebral artery and the suboccipital nerve lie in the middle

Which of the following would be indicative of a nerve injury or nerve involvement? Choose all that apply. - referred pain - sharp localized pain - deep ache - Shooting, burning pain - Numbness

- Shooting, burning pain - Numbness - referred pain

What is the name of the pain/temperature pathway? What is it's function? Ascending or descending? Ipsilateral or Contralateral?

- Spinothalamic Tract - Signals to the brain all changes in temperature and feelings of pain - Ascending (to thalamus) - Contralateral (crosses in the spinal cord)

What is the function of the atlas?

- Supports the head - Connects the vertebral column to the occipital bone - Allows a rocking motion forward and backward

What are the regional characteristics of the vertebrae: Sacral

-5 Fused Vertebrae = Median Sacral Crest -Anterior and Posterior -Sacral Foramen ~ intervertebral foramen -Sacral Canal ~ Vertebral Foramen

Hyperkyphosis

-An exaggerated outward curvature of the thoracic spine resulting in a rounded upper back (hunchback) -occurs with age

What are the regional characteristics of the vertebrae: Cervical

-Bífid spinous -Uncovertebral joint C3-C6 -Transverse Foramen: -vertebral arteries -Small body -Atlas: Flat, no body, -hold the skull -Axis: DENS -7 Vertebrae -Muchas Ligament

Where do you find uncovertebral joints?

-C3-C6 - form on the posterior side of the body along the uncus -prevent intervertebral disc from moving posteriorly and laterally

Most common cause of disc herniation:

Older individuals doing a movement of back flexion and rotation while load-bearing - can be triggered from microtrauma such as picking up a pencil or stepping off a curve - Happens within 5 days of a tear

What a Jefferson's Burst Fracture?

-Compression fracture of the arch of C1 - high impact on the top of the skull causes bone to break away from the spinal cord -not usually fatal

What does the posterior spinal artery derive from? What does it supply with blood?

-Derives from the PICA (Posterior Inferior cerebellar artery) - Supplies blood to the posterior 1/3 of the spinal cord

What is a dermatome vs a myotome?

-Dermatome: All skin innervated by one spinal nerve (sensory) -Myotome: All muscles innervated by one spinal nerve (motor)

What is the name of the sensory pathway? What is it's function? Ascending or descending? Ipsilateral or Contralateral?

-Dorsal Column Medial Lemniscus (DCML) - Touch, pressure, proprioception, vibration - Ascending (to thalamus) -Ipsilateral (crosses in the medulla)

What does the anterior spinal artery derive from? What does it supply with blood?

-derives from the vertebral arteries -Supplies blood to the anterior 2/3 of the spinal cord

What is a Hangman's fracture?

-fracture of the dens -always fatal -if the dens breaks the the skull can move freely and the spinal cord will be damaged

How many cranial nerves are there? Spinal nerves?

12, 31

What muscles originate and insert 2-4 segments at a time? What about 1-2? What about 4-6?

2-4: Multifidus 1-2: Rotators 4-6: Semispinalis

What is the lumbosacral angle?

30-50 degrees

Which vertebrae do not have bodies?

C1 and C2 or the atlas and axis

Secondary curves are usually found in which region(s) of the spine?

Cervical & Lumbar

Where are the two spinal cord enlargements found? Names?

Cervical Enlargement: -innervation for the upper extremity - brachial plexus (C4-T1) Lumbosacral Enlargement: -Innervation of the lower extremity- Cauda Equina (T11-S1)

What muscles are innervated via dorsal rami of the spinal nerves?

Deep Back "True"

When do secondary curvatures develop?

During infancy

Which nerve branches off of C2? What does it innervate?

Greater Occipital Nerve branches off of C2 and provides sensory information to the dermis of the posterior (or scalp) + neck + occipital region

Where does the herniation impinge on a spinal nerve- where is this found?

Happens specifically in the intervertebral foramen

What muscles are innervated via the intercostal nerves?

Intermediate Extrinsic - Serratus Posterior Superior: 1st Four Inferior: Last 4 Intercostals

What is a spinal tap?

Into the subarachnoid space: L3-L4 Ligamentum Flavum - Epidural Fat - Dura - Subdural - Arachnoid - subarachnoid space

Where does the spinal cord end?

L1-L2

Where does a herniated disc usually occur?

Lower back- most commonly L5-S1

Spinous processes in the sacrum fuse together to form which structure? -Auricular surface -articular processes -median sacral crest -sacral canal

Median Sacral Crest

Which nerve branches off of C1? What does it innervate?

Suboccipital nerve branches off of C1 and innervates the muscles of the suboccipital muscles

What muscles are innervated via the ventral rami of cervical spinal nerves?

Superficial Extrinsic Back Muscles

Which muscles are considered "True" intrinsic back muscles?

Superficial layer of Deep muscles: -Splenius Capitis -Splenius Cervicis Intermediate layer of Deep muscles: - Iliocostalis - Longissimus - Spinalis Deep layer of Deep muscles: - Semispinalis Thoracis - Semispinalis Cervacis - Semispinalis Capitis - Multifidi - Rotatores

Which muscles are considered Extrinsic back muscles?

These muscles act on the upper extremity: - Trapezius - Latissimus Dorsi - Rhomboideus Major - Rhomboideus Minor - Levator Scapulae

Primary curves are usually found in which region(s) of the spine?

Thoracic & Sacral

What is the arachnoid trabeculae?

Threads of connective tissue in subarachnoid space extending from the arachnoid membrane to the pia mater

T/F: The deep back muscles develop from the epimere and are innervated by dorsal primary rami.

True

Hypolordosis

reduction of normal lordotic curve, resulting in a flat-back appearance - occurs with spinal correcting surgeries

What attaches to the costal facet & demifacets?

ribs

What is the action of the right semispinalis capitis?

rotates the head and the neck to the side opposite the muscle -right rotates to left, left rotates to right -Semispinalis muscles have a contralateral lateral flexion and rotation movement

What structure runs through the transverse foramen?

vertebral artery